is now the shallow sunken bed of the North Sea. It is
probable that during the last great age, the Quaternary,
as geologists call it, the upheaval of what is now the
region of Siberia and Alaska, made a continuous chain of
land from Asia to America. As the land was depressed
again it left behind it the islands in the Bering Sea,
like stepping-stones from shore to shore. In the same
way, there was perhaps a solid causeway of land from
Canada to Europe reaching out across the Northern Atlantic.
Baffin Island and other islands of the Canadian North
Sea, the great sub-continent of Greenland, Iceland, the
Faroe Islands, and the British Isles, all formed part of
this continuous chain.

As the last of the great changes, there came the Ice Age,
which profoundly affected the climate and soil of Canada,
and, when the ice retreated, left its surface much as we
see it now. During this period the whole of Canada from
the Atlantic to the Rocky Mountains lay buried under a
vast sheet of ice. Heaped up in immense masses over the
frozen surface of the Hudson Bay country, the ice, from
its own dead weight, slid sidewise to the south. As it
went it ground down the surface of the land into deep
furrows and channels; it cut into the solid rock like a
moving plough, and carried with it enormous masses of
loose stone and boulders which it threw broadcast over
the face of the country. These stones and boulders were
thus carried forty and fifty, and in some cases many
hundred miles before they were finally loosed and dropped
from the sheet of moving ice. In Ontario and Quebec and